The next project on the household commode.

[dalehollow]

My supply line for our commode is currently on a on demand 12 volt pump from a stand pipe. This is for the commode only.

Trying to eliminate the 12 volt pump while on the dock.

IM not sure about the configuration. So IM assuming a couple check valves, fittings , some pex.

So if its not doable or problematic could use your thoughts thanks.

For those who missed my previous post, I just switched our straight drop for a standard household unit.

[GoVols]

So, if I'm reading right, you'll have 2 types of water delivery to the toilets: 1 for dock water, 1 for anchor water? Wouldn't keeping only 1 type of water delivery system be easier?

[Endurance]

Yes, some pex pipe and a tee will get dock water flowing to your toilet. You definitely want a check valve on the dock water line feeding your toilet. One reason is that you don't want to turn on your 12v pump only to have it run out your dock hose attachment point. But the more important reason is that you don't want lake water backflowing into your dock water system. You don't want to get sick on your boat and you surely don't want to be the guy that puts nasty stuff into the whole marina's water system. Making sure your 12v pump is off when you hook up to dock water will be a second safety measure, but you don't want to rely on that as your only safety.

Depending on the type of 12v pump you have, it will most likely act as your check valve to keep dock water from running out the bottom of your lakewater pickup tube.

This seems a simple enough setup and will lessen having to listen to the 12v pump and should also lessen toilet bowl cleaning from using lakewater. I would give some thought to how you're going to drain this system if it freezes in your part of the world. If you put in another tee and a drain valve, you might thank yourself next fall.

[dalehollow]

the system is working great, I put a check valve in front of the 12 volt pump.
I put a check valve on the supply line so the when the 12 volt kicks on it cant feed lake water into the fresh system.

freezing doesn't concern me, but this fall Ill follow up your advice an add the drain,

[waleed121]

I put a check valve on the supply line so the when the 12 volt kicks on it cant feed lake water into the fresh system.

[Tony B]

I hate to be the dark cloud to rain on your parade but.........pressure water directly from the dock could be a recipe for disaster.
I personally have seen 2 boats sunk from city water directly connected to a boat. The chance of this happening is fairly minimal, but it can happen, and when it does, it will happen quickly.